"LEGITIMIZING" LIONEL'S GP20, PART 2
COMPLETING THE 1:32 SCALE MODEL
BY GARY RAYMOND
IN THE LAST issue, I described how to lower the superstructure, rebuild the front and rear pilots, add and modify hardware, do some of the painting, and prepare the model for the final finish. Before we reach for the airbrush, we should add more details.
GRAB IRONS AND END RAILS
The standard diameter for grab irons is 3/4-inch; handrails are 1 inch in diameter. In 1:32 scale, those dimensions work out to .023- and .031-inch. The size must look consistent with other hardware on the model, though. Because I retained Lionel's existing .060-inch diameter handrails (double the correct size), I compromised by using .030-inch diameter brass rod for the grab irons (brass imports use .045-inch diameter rod for handrails).
Cut off the original plastic grab irons flush with the body. What remains will plug the mounting holes. Putty the holes and sand the area as flat as possible. Drill 1/32-inch holes (using a #66 bit) for the new parts. Note: Southern Pacific GP20s have an additional grab iron on the opposite side of the long hood and none on the short hood front. I used the old plugged holes as approximate locators and measured and marked the exact spacing.
The outside dimension of the grab irons is 18 inches (18/32-inch). The holes should be 17 scale inches wide and 19 scale inches apart. I had planned to make a jig to bend the grabs but forming them turned out easier and more consistent than I would have thought. I "calibrated" a needlenose pliers for correct bending points at various spots along its length. Then I bent the grab irons. Make some extras so you may pick the best ones. Each section of brass rod will produce ten grab irons.
Push the new grab irons into the holes you drilled. Pay attention to the direction of the rungs on top of the hoods. To make spacing jigs, cut four shims from 3/32-inch square Plastruct-two 3 inches long and two 3/4-inch long. Slide the long shims down the long hood behind the grab irons. They will keep each piece exactly the correct distance from the body. Use the short spacers to locate individual grab irons. Press in the brass firmly and adjust them so all are even. Apply PolyZap inside the shell where the brass pokes through the plastic wall. If any slight gaps appear around a rod from the outside you may fill them very carefully with more PolyZap on the tip of a toothpick.
You could place a bolt/washer casting above each arm of the grab irons but I found no casting appropriate to justify the time and effort.
Next, the end rails: Cut the loops Lionel provides for the chain flush with the inside stanchions. Slide the stanchions over enough to clear the cutters. Lionel apparently uses steel so I had to use 30 inch bolt cutters! What is more, I had to enlist the aid of my son, Bud, to position the cutters while I squeezed. When you have cut and cleaned up the rails, slide the stanchions back in place and cement jewelry chain to the cut ends with PolyZap.
I also replaced the pilot rails. If you are modeling a new (1959-60 era) GP20, cut off the plastic pilot rails and replace them with .045-inch brass wire. Paint the new rail white. If you are modeling a geep from the 1970s, paint the new rail gray. If your model represents a locomotive from the 1980s, it would have no pilot rails. [Or footboards.-Ed.]
I modeled a pre-1980 style of coupler lift bar. Mount the lift bars a scale 12 inches (12/32-inch) below the deck. I added chain to the center where it attaches to the coupler even though a large link would have been more correct.
For the brackets, I used Grandt Line On3 scale lift rings. Their shape is actually wrong but the size is right and they work well. Slide two rings onto each end of the lift bar and keep them from falling off with a small piece of masking tape. Drill four holes in each pilot along the centerline of the shim and near the bends in the lift bar. Use a #70 bit. If you locate the brackets properly you should notice very little sideplay. Use the tip of a toothpick to apply a tiny drop of PolyZap to each hole; capillary action will draw it in. Push in each bracket and use a needlenose pliers to align it.
The brake lines connecting the cylinders on the truck sideframes are .031-inch diameter brass rod and you'll need four. Drill a hole in the center of each brake cylinder, then press fit the lines. Apply two drops of PolyZap to an inconspicuous spot on the top of the sideframe to keep the lines from twisting.
Now it is time to paint whatever parts remain. Align the handrail stanchions and mask the white ends. I applied gray paint first, then the red. It is a full size template of the nose striping. Use the copy as a taping template. Be sure the copy machine reproduces the template to precise size.
Paint the short hood before you reassemble the model. The secret to achieving very clean lines is careful masking. I used Bishop Graphics drafting tape because of its excellent quality. It is very flexible but, if you apply it correctly, it will prevent the paint from "feathering".
Begin with 1/16-inch wide tape for the edges. I used many pieces to insure I had everything exactly the way I wanted it. (I would rather spend more time masking than trying to correct overspray mistakes!)
A note about the location of the vertical edge of the red paint on the long hood: I chose to use the ridge Lionel created on the shell casting because it gave me an easier line to mask and tends to camouflage the sharp edge lines on the shell. The paint scheme on the full size locomotives has a smooth radius instead of sharp angles at the transitions. Run the edge of the red paint up to the first hatch seam on the long hood, then straight over the top to simplify the masking on top of the long hood. Refer to the photos.
When you airbrush the underside of the model, avoid painting the speaker cone or the gasket.
Once you have installed the handrails, realign them and touch up any spots. Be sure you mask all windows and lights carefully. I found 3 x 5 index cards useful for various masking jobs.
Locate the bottom of the big SP dry transfer 11/32-inch above the front deck. The edge of the "P" goes on the break of the nose. The bottom of the cab numbers should sit 1/8-inch above the bottom edge of the cab and 15/32 from each side. Center the "SOUTHERN PACIFIC" long hood transfer under the dynamic brake and the middle row of hinges. The bottom of the rear number sits 1 5/16-inch above the deck. Apply the number board numerals slightly off center so they appear centered in the housing.
Use heat shrink rather than tape to insulate all the wires when you reconnect them. You could also use connectors if you plan to disassemble the engine often.
Remount the speaker, being careful to clear any debris from the cavity. Be sure the speaker gasket makes an airtight seal. Replace the speaker backplate and the lead weight. Replace the trucks. The two long screws secure the weight, the two shorter ones are for the trucks.
Reconnect all motor wiring. If you labeled all wires carefully, you should have no problem. I strongly recommend you add working "M.U." (multiple unit) cables to all your diesels. If you run two or more engines together, it will make a big difference in performance. I explained the procedure in my article "Working M/U Cables", Garden Railways, September/October, 1991. The cables require you drill 5/64-inch holes through the pilots. Locate the holes so the cables come out under the dummy M.U. cable fittings. Two of the photos show how. Paint the cable brackets the same color as the body. Lightly airbrush the dummy cables Grimy Black to match the Belden cable. Spray the dummy connectors Floquil "Old Silver", then overspray them with Grimy Black to match the real M.U. connectors. Tuck the real M.U. cables under the dummies to keep them from sticking out when they are not in use.
Press the number board housing in place. Push the number board light assembly into place. Replace the beacon dome. I trimmed the keepers down slightly to get them in.
Assemble the rear wall to the cab floor. Push up the cab "windows" as far as possible, making sure all the wiring feeds neatly along the roof. Clean the inside of the windows!
Attach the floor assembly. Push the cab into place. Keep the handrail ends from scratching the paint. Press in the handrails and re-straighten the stanchions. Add the short hood and fasten it with three screws. Replace the front and rear headlight lenses. Trim about 1/16-inch from the sides of the rear number board and cut off the sides and the number portion if you are modeling a Southern Pacific diesel.
Before tightening down the circuit board, raise the chassis and support it under the fuel tank and on each side of the speaker opening. Let the chassis ends with the trucks hang down. Then tighten the circuit board. Lionel uses it as a structural truss and reassembling it in this way will help de-stress the chassis when the engine sits on the rail.
Slide the shell down over the chassis, making sure all the wires are inside. Check for a tight fit. You may have to do some internal trimming on the ends (where you modified the pilot) for a flush fit. Then turn over the engine and install the eight screws.
Next, do an electrical check. Connect a power pack to the M.U. cables. If you have built more than one engine, as I did, you may connect them all together and check all at once. That is a particularly good idea for seeing if all the wheels are turning at the same speed. Also be sure they all turn in the same direction and notice whether all the lights work. Reverse polarity and check again. Also check the sound system.
I decided to leave the body with a flat finish although a semi-gloss would be appropriate for a newer locomotive. I used dark gray chalk to add subtle streaks of dirt and black chalk to darken the fan and hatch grills. I lightly airbrushed the turbo stack with Floquil Engine Black. Then I added rust colored chalk to the truck sideframes, painted the couplers with Floquil Rust, and oversprayed them with Grimy Black.
A couple of final thoughts after having run the finished diesels:
When you cut the center truck bolster shafts to lower the body over the trucks, be sure they are just slightly higher than the truck brake cylinders. Otherwise add a nylon washer to take the weight of the body at those two points. My diesel bodies rest on the four brake cylinders on each truck, creating excess friction when the engine rolls into a curve.
Recheck coupler height and, if necessary, add a couple of body stabilizers (plastic pieces on each side on one truck only) to eliminate wobble.
The cab light should be dimmer. Replace the bulb with one of higher voltage or add a resistor in series with either bulb lead.
If you use LGB track power terminals, replace them with something that doesn't protrude above the rail height. The Lionel trucks sit low and wide and will hit the protrusion. Note: That is a problem with the stock engines; it has nothing to do with the modifications we made in the article.
Functioning M.U. cables are a must, since multiple engines do not respond uniformly to track power even with clean wheels.
I want to thank the following people without whose help the models would never have turned out so well: Russ Reinberg for providing an overview as to the scope of the project, various modeling tips, and the photos; Bob Uniack for additional modeling techniques and judgment; Bob Smaus whose article on modernizing an HO scale GP9 (Railroad Model Craftsman, March, 1990) offered a valuable starting point for construction; Maynard Priest at Allied Model Trains in Los Angeles for helping with Southern Pacific paint details; Marty's Hobbies in Thousand Oaks, The Whistle Stop in Pasadena, and Kit Kraft Hobbies in North Hollywood for materials; and Bob Crone for his research on Southern Pacific locomotive numbering.